Publications

demonstration of lateral transmission of scrapie between sheep kept under natural conditions using lymphoid tissue biopsy.	scrapie free adult sheep were introduced to a sheep flock specifically maintained to maximise scrapie infection. native born sheep of the highly susceptible vrq/vrq genotype in this flock show highly efficient transmission, evidenced by 100% infection, with an age at death of less than 2 years. infection in introduced sheep was identified by biopsy of tonsilar and nictitating membrane lymphoid tissue. progeny of these sheep were monitored and clinical disease confirmed by examination of the brai ...	2004	15046955
estimation of scrapie prevalence in cull and found-dead sheep on the shetland islands.		2004	15053138
decision support tools for clinical diagnosis of disease in cows with suspected bovine spongiform encephalopathy.	reporting of clinically suspected cattle is currently the most common method for detecting cases of bovine spongiform encephalopathy (bse). improvement of clinical diagnosis and decision-making remains crucial. a comparison of clinical patterns, consisting of 25 signs, was made between all 30 bse cases, confirmed in belgium before october 2002, and 272 suspected cases that were subsequently determined to be histologically, immunohistochemically, and scrapie-associated-fiber negative. seasonality ...	2004	14715749
reduced proteinase k resistance and infectivity of prions after pressure treatment at 60 degrees c.	high hydrostatic pressure is a mild technology compared with high temperatures and is commonly used for food pasteurization. crude brain homogenates of terminally diseased hamsters infected with scrapie 263k strain were heated at 60 degrees c and/or pressurized up to 1000 mpa for 2 h. prion proteins were analysed for their proteinase k sensitivity using a western blot technique. prp(sc) pressurized with 500 mpa or above proved to be proteinase k sensitive. to test the remaining infectivity of th ...	2004	14718641
quinoline derivatives are therapeutic candidates for transmissible spongiform encephalopathies.	we previously reported that quinacrine inhibited the formation of an abnormal prion protein (prpres), a key molecule in the pathogenesis of transmissible spongiform encephalopathy, or prion disease, in scrapie-infected neuroblastoma cells. to elucidate the structural aspects of its inhibiting action, various chemicals with a quinoline ring were screened in the present study. assays of the scrapie-infected neuroblastoma cells revealed that chemicals with a side chain containing a quinuclidine rin ...	2004	14722283
neurons and astrocytes respond to prion infection by inducing microglia recruitment.	the accumulation and activation of microglial cells at sites of amyloid prion deposits or plaques have been documented extensively. here, we investigate the in vivo recruitment of microglial cells soon after intraocular injection of scrapie-infected cell homogenate (hgtsc+) using immunohistochemistry on retinal sections. a population of cd11b/cd45-positive microglia was specifically detected within the ganglion and internal plexiform retinal cell layers by 2 d after intravitreal injection of hgt ...	2004	14736847
flexible n-terminal region of prion protein influences conformation of protease-resistant prion protein isoforms associated with cross-species scrapie infection in vivo and in vitro.	transmissible spongiform encephalopathy (tse) diseases are characterized by the accumulation in brain of an abnormal protease-resistant form of the host-encoded prion protein (prp), prp-res. prp-res conformation differs among tse agents derived from various sources, and these conformational differences are thought to influence the biological characteristics of these agents. in this study, we introduced deletions into the flexible n-terminal region of prp (residues 34-124) and investigated the ef ...	2004	14736880
susceptibility of common fibroblast cell lines to transmissible spongiform encephalopathy agents.	the risk of contamination of tissue culture cells with transmissible spongiform encephalopathy (tse) agents as a result of the use of animal products as medium components has been considered to be low, in part, because only a few brain-derived cell lines have been reported to be susceptible to tse infection. in the present study, we demonstrate that the common laboratory fibroblast cell lines nih/3t3 and l929, which express low levels of cellular mouse prion protein, are susceptible to infection ...	2004	14745700
mutant prpsc conformers induced by a synthetic peptide and several prion strains.	gerstmann-sträussler-scheinker (gss) disease is a dominantly inherited, human prion disease caused by a mutation in the prion protein (prp) gene. one mutation causing gss is p102l, denoted p101l in mouse prp (moprp). in a line of transgenic mice denoted tg2866, the p101l mutation in moprp produced neurodegeneration when expressed at high levels. moprp(sc)(p101l) was detected both by the conformation-dependent immunoassay and after protease digestion at 4 degrees c. transmission of prions from th ...	2004	14747574
immunogold electron microscopy recognizes prion protein-associated particles prepared from scrapie-infected mouse brain.	previous studies have proposed that the disease isoform of prion protein (prpsc) is particulate. our purpose was to search by electron microscopy (em) for particles in fractions of density gradients prepared from differentially centrifuged homogenates of scrapie-infected, normal, and null mouse brain. only mild detergents were used during the separation process. the low-density fractions derived from scrapie-infected brain were rich in prp. three morphologically distinct types of particle were o ...	2004	14748559
scrapie-infected gt1-1 cells show impaired function of voltage-gated n-type calcium channels (ca(v) 2.2) which is ameliorated by quinacrine treatment.	prions are transmissible pathogens that cause neurodegenerative diseases, although the mechanisms behind the nervous system dysfunctions are unclear. to study the effects of a prion infection on voltage-gated calcium channels, scrapie-infected gonadotropin-releasing hormone neuronal cells (scgt1-1) in culture were depolarized by kcl and calcium responses recorded. lower calcium responses were observed in infected compared to uninfected cells. this effect was still observed when l-type calcium ch ...	2004	14751779
bse control: detection of gelatine-derived peptides in animal feed by mass spectrometry.	the epidemic of bovine spongiform encephalopathy (bse) is thought to have resulted from feeding scrapie-infected sheep to cattle. this has led to a ban of feeding animals with "processed animal protein"(pap). we report a novel approach for the mass spectrometric detection of pap contamination in animal feedstuffs by detecting gelatine, a derivative of the major animal protein collagen. a method was developed to hydrolyse gelatine standards with hydrochloric acid, followed by detection of the der ...	2004	14752552
prion protein gene polymorphisms in healthy and scrapie-affected sheep in greece.	a total of 216 local crossbred sheep from 16 scrapie-affected greek flocks and 210 purebred sheep of the milk breeds chios and karagouniko from healthy flocks were analysed for scrapie-linked polymorphisms in the prion protein (prp) gene. of the 216 sheep in this case-control study, 96 sheep were clinical cases, 25 subclinical cases (asymptomatic at the moment of euthanasia but positive by histopathology and/or elisa detecting proteinase-resistant prp) and 95 healthy controls (negative by all ev ...	2004	14769911
[comments on present-day spread and epidemiology of bse and prion diseases].	prion diseases of animals and man are neurological diseases with amyloidal deposition of the respective proteins. as to prion disease, the cellular prion protein is in its abnormal isoform(s) an essential component of prion protein aggregates found in affected tissue. in contrast to all neurodegenerative diseases like morbus alzheimer or huntington's disease, prion diseases are transmissible. therefore, prion diseases were designated transmissible spongiform encephalopathies (tse). the diseases ...	2004	14770333
frequencies of prion protein (prp) genotypes and distribution of ages in 15 scrapie-affected flocks in great britain.	the frequencies of prion protein (prp) genotypes were investigated in 15 scrapie-affected flocks in great britain. the flocks were heterogeneous in the frequencies of different genotypes and alleles, and in their age distributions. the median flock frequency of animals with vrq-containing genotypes was 21 per cent (range 2 to 82 per cent, mean 25 per cent). the vrq-containing and other non-arr genotypes made up 11 to 82 per cent of a flock (median 46 per cent, mean 48 per cent). in comparison wi ...	2004	14725423
detection of prpsc on lymphoid tissues from naturally affected scrapie animals: comparison of three visualization systems.	we assessed three different visualization systems used routinely in research and diagnosis of transmissable spongiform encephalopathies (tses) to demonstrate whether the methodology applied to immunohistochemical (ihc) examination may alter the results concerning detection of prion protein (prpsc) in the lymphoreticular system (lrs): avidin-biotin-peroxidase (vectastain abc kit; vector), envision (dako), and catalyzed signal amplification (csa; dako). the study aimed to determine which of these ...	2004	14729865
binding of prion proteins to lipid membranes.	a key molecular event in prion diseases is the conversion of the normal cellular form of the prion protein (prpc) to an aberrant form known as the scrapie isoform, prpsc. under normal physiological conditions prpc is attached to the outer leaflet of the plasma membrane via a gpi-anchor. it has been proposed that a direct interaction between prp and lipid membranes could be involved in the conversion of prpc to its disease-associated corrupted conformation, prpsc. recombinant prp can be refolded ...	2004	14697227
antibody to dna detects scrapie but not normal prion protein.	prion diseases, a group of fatal neurodegenerative disorders, are characterized by the presence of the abnormal scrapie isoform of prion protein (prp(sc)) in affected brains. a conformational change is believed to convert the normal cellular prion protein into prp(sc). detection of prp(sc) for diagnosis and prophylaxis is impaired because available abs recognizing epitopes on prp fail to distinguish between prp(sc) and normal cellular prion protein. here, we report that an anti-dna ab, ocd4, as ...	2004	14734804
copper induces increased beta-sheet content in the scrapie-susceptible ovine prion protein prpvrq compared with the resistant allelic variant prparr.	prion diseases are characterized by conformational change in the copper-binding protein prp (prion protein). polymorphisms in ovine prp at amino acid residues 136, 154 and 171 are associated with variation in susceptibility to scrapie. prpvrq [prp(val136/arg154/gln171)] or prparq [prp(ala136/arg154/gln171)] animals show susceptibility to scrapie, whereas those that express ala136/arg154/arg171 (prparr) show resistance. results are presented here that show prpvrq and prparr display different conf ...	2004	14969585
strain-specific kinetics of prion protein formation in vitro and in vivo.	the molecular basis of prion strain diversity is proposed to be encoded by distinct conformations of the abnormal scrapie isoform of the prion protein (prp(sc)). prp(sc) formation for the hyper (hy) and drowsy (dy) strains of the transmissible mink encephalopathy (tme) agent was investigated using the cell-free prp conversion reaction to determine the role of distinct prp(sc) conformations in the rate of in vitro conversion of cellular prp into protease-resistant prp. prp conversion increased at ...	2004	14573620
cultured peripheral neuroglial cells are highly permissive to sheep prion infection.	transmissible spongiform encephalopathies arise as a consequence of infection of the central nervous system (cns) by prions. spreading of the infectious agent through the peripheral nervous system (pns) may represent a crucial step toward cns neuroinvasion, but the modalities of this process have yet to be clarified. here we provide further evidence that pns glial cells are likely targets for infection by prions. glial cell clones originating from dorsal root ganglia of transgenic mice expressin ...	2004	14671128
the occurrence of vacuolation, and periodic acid-schiff (pas)-positive granules and plaques in the brains of c57bl/6j, akr, senescence-prone (samp8) and senescence-resistant (samr1) mice infected with various scrapie strains.	scrapie is a fatal, but slow, infectious disease. c57bl/6j, samp8 (a strain that develops early senescence), samr1 (a strain that is resistant to senescence) and akr/j (a progenitor of the sam strains) mice were infected with 22a, 139a, 22l and me7 scrapie strains. histopathological stains included haematoxylin and eosin (he), and periodic acid-schiff (pas). vacuolation was found in the brains of all scrapie-infected mice. the 22a strain caused more extensive vacuolation in the brains of samp8 a ...	2004	14672805
prpsc binding antibodies are potent inhibitors of prion replication in cell lines.	conversion of the cellular alpha-helical prion protein (prp(c)) into a disease-associated isoform (prp(sc)) is central to the pathogenesis of prion diseases. molecules targeting either normal or disease-associated isoforms may be of therapeutic interest, and the antibodies binding prp(c) have been shown to inhibit prion accumulation in vitro. here we investigate whether antibodies that additionally target disease-associated isoforms such as prp(sc) inhibit prion replication in ovine prp-inducibl ...	2004	15133046
acute formation of protease-resistant prion protein does not always lead to persistent scrapie infection in vitro.	transmissible spongiform encephalopathies are accompanied by the accumulation of a pathologic isoform of a host-encoded protein, termed prion protein (prp). despite the widespread distribution of the cellular isoform of prp (protease-sensitive prp; prp-sen), the disease-associated isoform (protease-resistant prp; prp-res) appears to be primarily restricted to cells of the nervous and lymphoreticular systems. in order to study why scrapie infection appears to be restricted to certain cells, we fo ...	2004	15133048
scrapie-infected cells, isolated prions, and recombinant prion protein: a comparative study.	fourier -transform infrared microscopic spectra of scrapie-infected nervous tissue measured at high spatial resolution (approximately 6 microm) were compared with those obtained from the purified, partly proteinase k digested scrapie isoform of the prion protein isolated from nervous tissue of hamsters infected with the same scrapie strain (263k) to elucidate similarities/dissimilarities between prion structure investigated in situ and ex vivo. a further comparison is drawn to the recombinant sy ...	2004	15137116
selective and efficient immunoprecipitation of the disease-associated form of the prion protein can be mediated by nonspecific interactions between monoclonal antibodies and scrapie-associated fibrils.	transmissible spongiform encephalopathies are characterized by the accumulation in brain tissues of an abnormal isoform of the prion protein named prpsc, which is the only direct marker known for transmissible spongiform encephalopathies. here we show that prpsc can be specifically immunoprecipitated by using several monoclonal antibodies (mabs) of various specificities independently of the properties of their binding site (paratope). these results strongly suggest that a significant proportion ...	2004	15140886
activity of an alkaline 'cleaner' in the inactivation of the scrapie agent.	the capacity of a routinely available alkaline cleaner for medical devices to inactivate the causative agent of a transmissible spongiform encephalopathy (tse) was tested. the co-incubation of brain homogenates, prepared from terminally ill scrapie-infected hamsters, with the cleaner led to the denaturation of misfolded protein as the proteinase k-resistant prion protein was no longer detectable after such treatment. in addition, intra-cerebral inoculation of hamsters with the alkaline cleaner-t ...	2004	15142720
preclinical deposition of pathological prion protein prpsc in muscles of hamsters orally exposed to scrapie.	recently, pathological prion protein prp(sc), the putative key constituent of infectious agents causing transmissible spongiform encephalopathies (tses), was found in muscles of rodents experimentally infected with scrapie and in patients with creutzfeldt-jakob disease (cjd). for the assessment of risk scenarios originating from these findings (e.g., alimentary transmission of pathogens associated with bovine spongiform encephalopathy [bse] and chronic wasting disease [cwd] via tainted beef and ...	2004	15146244
classical and alternative pathway complement activation are not required for reactive systemic aa amyloid deposition in mice.	during induction of reactive systemic amyloid a protein (aa) amyloidosis in mice, either by chronic inflammation or by severe acute inflammation following injection of amyloid enhancing factor, the earliest deposits form in a perifollicular distribution in the spleen. because the splenic follicular localization of immune complexes and of the scrapie agent are both complement dependent in mice, we investigated the possible complement dependence of aa amyloid deposition. in preliminary experiments ...	2004	15147568
pathology and pathogenesis of bovine spongiform encephalopathy and scrapie.	in common with other prion diseases or transmissible spongiform encephalopathies (tses), scrapie of sheep and bovine spongiform encephalopathy (bse) are characterized by grey matter vacuolation and accumulation of an abnormal isoform of the host prion protein (prp) in the central nervous system (cns). in apparent contrast with human disease, neither neuronal loss nor gliosis are invariable features of the pathology of domestic food animal tses. in sheep, accumulation of abnormal prp may also occ ...	2004	15148988
chronic wasting disease of cervids.	chronic wasting disease (cwd) has recently emerged in north america as an important prion disease of captive and free-ranging cervids (species in the deer family). cwd is the only recognized transmissible spongiform encephalopathy (tse) affecting free-ranging species. three cervid species, mule deer (odocoileus hemionus), white-tailed deer (o. virginianus), and rocky mountain elk (cervus elaphus nelsoni), are the only known natural hosts of cwd. endemic cwd is well established in southern wyomin ...	2004	15148993
unique amino acid polymorphisms of prp genes in mongolian sheep breeds.	to characterize amino acid polymorphisms of sheep prion protein (prp) gene, dna from 740 sheep of nine breeds raised in mongolia was isolated and analyzed. a total of 16 genotypes and seven allelic variants of the prp gene at codons 112, 136, 154, and 171 were found. the marq/marq genotype associated with susceptibility to scrapie was found in 82.6% of the sheep while the marr/marr genotype associated with resistance to scrapie was found in 1.8% of the sheep. the polymorphisms of valine and seri ...	2004	15528869
characterization of a complex formed between human plasminogen and recombinant sheep prion: pressure and thermal sensitivity of complex formation.	scrapie is thought to be caused by one or more conformations of a proteinacious particle called a prion. the infectious form(s) is referred to as the scrapie form of the prion protein (prpsc) whereas a benign form, the cellular conformer, is referred to as prpc. the cellular conformation of the sheep prion protein formed a 1:1 complex with human plasminogen. the complex precipitated at 0 degrees c (ksp = 17* 10(-12) m2). this precipitation reaction was sensitive to both temperature and pressure. ...	2004	15529749
alterations of somatotropic function in prion disease in sheep.	this study aimed at investigating the possible linkage between natural scrapie and alterations of the somatotropic axis. scrapie-affected ewes exhibited 2-fold higher mean gh concentrations during both autumn and spring. gh pulse frequencies were higher in scrapie-affected ewes than in control animals (mean+/-s.e.m. number of pulses/24 h: 10.4+/-0.9 and 7.6+/-0.9 for scrapie-affected and control ewes respectively) suggesting the involvement of central mechanisms. gh secretion induced by administ ...	2004	15531730
the first canadian indigenous case of bovine spongiform encephalopathy (bse) has molecular characteristics for prion protein that are similar to those of bse in the united kingdom but differ from those of chronic wasting disease in captive elk and deer.	brain tissue from a case of bovine spongiform encephalopathy (bse) from alberta was subjected to a western immunoblotting technique to ascertain the molecular profile of any disease-specific, abnormal prion protein, that is, prion protein that is protease-resistant (prp(res)). this technique can discriminate between isolates from bse, ovine scrapie, and sheep experimentally infected with bse. isolates of brain tissue from the bse case in alberta, 3 farmed elk with chronic wasting disease (cwd) f ...	2004	15532881
nucleic acid and prion protein interaction produces spherical amyloids which can function in vivo as coats of spongiform encephalopathy agent.	the infectious agent of transmissible spongiform encephalopathies (tse) has been considered to be prp(sc), a structural isoform of cellular prion protein prp(c). prp(sc) can exist as oligomers and/or as amyloid polymers. nucleic acids induce structural conversion of recombinant prion protein prp and prp(c) to prp(sc) form in solution and in vitro. here, we report that nucleic acids, by interacting with prp in solution, produce amyloid fibril and fibres of different morphologies, similar to those ...	2004	15533448
postal questionnaire survey of scrapie in sheep flocks in ireland.		2004	15537145
possible role of region 152-156 in the structural duality of a peptide fragment from sheep prion protein.	the conformational conversion of the nonpathogenic "cellular" prion isoform into a pathogenic "scrapie" protease-resistant isoform is a fundamental event in the onset of transmissible spongiform encephalopathies (tse). during this pathogenic conversion, helix h1 and its two flanking loops of the normal prion protein are thought to undergo a conformational transition into a beta-like structure. a peptide spanning helix h1 and beta-strand s2 (residues 142-166 in human numbering) was studied by cir ...	2004	15537751
associations between the prion protein genotype and performance traits of meat breeds of sheep.	the prion protein (prp) genotypes of four german meat breeds of sheep were examined in relation to their scores for muscle mass, conformation, wool quality, daily liveweight gain and ultrasonic measurements of the depth of back muscle and back fat. the dataset included 912 genotyped german texel sheep among 10,383 recorded sheep, 474 genotyped suffolk sheep among 4079 recorded sheep, 271 genotyped german white-headed mutton sheep among 3393 recorded sheep, and 99 genotyped german black-headed mu ...	2004	15338706
[influence of ultrasonic processing on the aggregation of prp-sc in the brain extracts of the scrapie-infected hamsters].	to evaluate the influence ultrasonic processing on the aggregation of prp(sc) in the brain extracts prepared from the scrapie-infected hamsters, and to seek for the way to prepare lower molecular prp(sc) polymer.	2004	15340496
evaluation of anti-prion activity of congo red and its derivatives in experimentally infected hamsters.	among transmissible spongiform encephalopathies (tse), particularly dreadful are the bovine spongiform encephalopathy (bse), because of its epidemic character, and the new variant of creutzfeldt-lakob disease (vcjd) in man, possibly related to bse prion, through the intake of infected food. to treat tse, many potentially therapeutic agents have been tested: some of them, among which is congo red (cas 573-58-0, cr), delayed the onset of symptoms in scrapie-infected rodents, and some cr derivative ...	2004	15344846
a robust, low- to medium-throughput prnp genotyping system in sheep.	in many countries breeding programs for resistance to scrapie in sheep are established. therefore, the demand on genotyping capacities of the polymorphisms of the prion protein gene (prnp) relevant to presently known disease associations and eu regulations is steadily increasing. most published typing methods are not well suited for routine typing of large sample numbers in smaller service laboratories for different reasons: they require partly manual data processing, sophisticated and sensitive ...	2004	15345029
the role of prp in health and disease.	transmissible spongiform encephalopathies (tses) such as scrapie in sheep, bovine spongiform encephalopathy (bse) in cattle or creutzfeldt-jacob disease (cjd) and gerstmann-sträussler-scheinker syndrome (gss) in humans, are caused by an infectious agent designated prion. the "protein only" hypothesis states that the prion consists partly or entirely of a conformational isoform of the normal host protein prpc and that the abnormal conformer, when introduced into the organism, causes the conversio ...	2004	15354865
impacts and concerns for vcjd in blood transfusion: current status.	the impact of vcjd upon blood transfusion practice hinges on its lymphoreticular involvement. b lymphocytes play a key supporting role for the capture and replication of infectivity by follicular dendritic cells of the lymphoid tissue in animal models of transmissible spongiform encephalopathies (tse) and tonsils, spleen and appendix in man can harbour vcjd infectivity, a situation not seen with the other human tses. leucodepletion of blood donations in the uk was implemented to reduce possible ...	2004	15354867
the genetics of scrapie in sheep and goats.	scrapie, an invariably fatal disease of sheep and goats, is a transmissible spongiform encephalopathy (tse). the putative infectious agent is the host-encoded prion protein, prp. the development of scrapie is closely linked to polymorphisms in the host prp gene. the pathogenesis of most tses involves conversion of normal, cellular prp into a protease-resistant, pathogenic isoform called prpsc. the conversion to prpsc involves change in secondary structure; it is impacts on these structural chang ...	2004	15354869
genetic variability of the prp gene in a goat herd in the uk.		2004	15357379
prion diseases and the spleen.	transmissible spongiform encephalopathies are fatal neurodegenerative disorders that include creutzfeldt-jakob disease in humans, bovine spongiform encephalopathy and scrapie in sheep and goats. transmissible spongiform encephalopathies are thought by some to result from changes in the conformation of a membrane glycoprotein called prpc (prion protein) into a pathogenic form, prpsc, which constitutes the major component of an unprecedented type of infectious particle supposedly devoid of nucleic ...	2004	15357900
alkaline serine protease produced by streptomyces sp. degrades prp(sc).	a prp(sc)-degrading enzyme was isolated from the culture medium of streptomyces sp. using perchloric acid-soluble protein (psp) as a substrate. the media of 500 microbial species were screened to obtain the psp-degrading enzyme. the medium containing the protease secreted from strain 99-gp-2d-5 showed the highest psp-degrading activity. strain 99-gp-2d-5 was assigned as the genus streptomyces by its morphological and chemotaxonomic characteristics. when scrapie prion was used as the substrate, i ...	2004	15358213
gene expression profiling of scrapie-infected brain tissue.	the underlying pathomechanisms in prion infections of the central nervous system are still insufficiently understood. the identification of genes with altered expression patterns in the diseased brain may provide insight into the disease development on the molecular level, which ultimately leads to neuronal loss. to provide a detailed analysis of changes in the molecular level in prion disease pathology we used a large-scale gene array based approach, which covers more than 11,000 functionally c ...	2004	15369787
glycosylation deficiency at either one of the two glycan attachment sites of cellular prion protein preserves susceptibility to bovine spongiform encephalopathy and scrapie infections.	the conversion into abnormally folded prion protein (prp) plays a key role in prion diseases. prp(c) carries two n-linked glycan chains at amino acid residues 180 and 196 (mouse). previous in vitro data indicated that the conversion process may not require glycosylation of prp. however, it is conceivable that these glycans function as intermolecular binding sites during the de novo infection of cells on susceptible organisms and/or play a role for the interaction of both prp isoforms. such recep ...	2004	15448157
low frequency of the scrapie resistance-associated allele and presence of lysine-171 allele of the prion protein gene in italian biellese ovine breed.	frequencies of polymorphisms at codons 136, 154 and 171 of the prion protein (prp) gene were studied in 1207 pure-bred and cross-bred italian biellese rams, a small ovine breed of about 65 000 head in italy. aside from the five most common alleles (vrq, arq, arr, ahq and arh), the rare ark allele was also found, with the highest frequency reported so far in an ovine breed (2.5 %). ark/--- genotypes had a total frequency of 4.9 %. the resistance-associated arr allele was seen at a low frequency ( ...	2004	15448380
molecular approaches to mechanisms of prion diseases.	prion diseases such as scrapie in sheep, bovine spongiform encephalopathy in cattle, creutzfeldt-jakob disease, gerstmann-sträussler-scheinker disease and fatal familial insomnia in man are neurodegenerative disorders. in humans, the diseases can be sporadic, inherited, or acquired by infection. the underlying pathogenic event in prion diseases is a conformational modification of the cellular isoform prion protein (prp(c)) to the pathogenic isoform (prp(sc)) that accumulates in the central nervo ...	2004	15449458
oligomerization of the proteolytic products is an intrinsic property of prion proteins.	in the present study we show that the oligomerization of the proteolytic products is an intrinsic property of prion proteins. no such oligomerization was observed for the proteolytic products of other proteins after identical treatment. the rate of enzymatic hydrolysis of recombinant human (rhprp) (23-231) and golden hamster (rmaprp) (23-231) prion proteins as well as that of rmaprp (90-231), corresponding to the infectious fragment of the scrapie form, drastically increases in the presence of c ...	2004	15451435
identification of differentially expressed genes in scrapie-infected mouse brains by using global gene expression technology.	the pathogenesis of prion diseases, a class of transmissible fatal neurodegenerative diseases in humans and animals, is still unclear. the aim of this study was to identify the differentially regulated genes that correlate with the development of prion diseases for a better understanding of their pathological mechanisms. we employed affymetrix mouse expression arrays 430a containing >22,000 transcripts and compared the global gene expression profiles from brains of mice who were intracerebrally ...	2004	15452225
attributable testing for abnormal prion protein, database linkage, and blood-borne vcjd risks.	context: national prospective collection of tonsillar tissue to be tested anonymously for abnormal lymphoreticular accumulation of prion protein (prp) was approved to begin in the uk in 2004. the uk is not, however, testing autopsy specimens attributably for abnormal prp (prp(sc)) so that recipients at risk after a blood transfusion from, or exposed to surgical instruments from, a deceased carrier of variant creutzfeldt-jakob disease (vcjd) can be followed up to quantify transmission risks. in s ...	2004	15474140
preventing misfolding of the prion protein by trimethylamine n-oxide.	transmissible spongiform encephalopathies are a class of fatal neurodegenerative diseases linked to the prion protein. the prion protein normally exists in a soluble, globular state (prp(c)) that appears to participate in copper metabolism in the central nervous system and/or signal transduction. infection or disease occurs when an alternatively folded form of the prion protein (prp(sc)) converts soluble and predominantly alpha-helical prp(c) into aggregates rich in beta-structure. the structura ...	2004	15476389
synthesis of analogues of congo red and evaluation of their anti-prion activity.	no cure as of yet exists for any of the transmissible spongiform encephalopathies. in this paper, we describe the synthesis of analogues of congo red and evaluation against a cellular model of infection, the smb (scrapie mouse brain) persistently infected cell line, for their ability to inhibit the infectivity of the abnormal form of prion protein (prp-res). the compounds have also been tested for their ability to inhibit the polymerization of prpc by prp-res. a number of analogues showed inhibi ...	2004	15481988
identification of central nervous system genes involved in the host response to the scrapie agent during preclinical and clinical infection.	genes that are expressed differentially in the central nervous system of mice during infection with mouse-adapted scrapie agents were identified in this study. cdna microarrays were used to examine gene-expression profiles at early, middle (preclinical) and late (clinical) time points after inoculation. a number of genes that showed significant changes in expression during the clinical stage of disease were identified. of these, 138 were upregulated and 20 were downregulated. a smaller number of ...	2004	15483264
abnormal prion protein in genetically resistant sheep from a scrapie-infected flock.	the central molecular event in transmissible spongiform encephalopathies, such as scrapie in sheep, is the accumulation in tissues of an abnormal isoform of the cellular prion protein. a previous investigation of 26 sheep showed that the accumulation of prp(res) in brain correlated more with the prnp genotype than with the severity of the clinical disease. here, the ability of a sandwich elisa to detect prp(res) distribution in the brain was demonstrated. immunohistochemistry also strongly suppo ...	2004	15483266
identification of putative atypical scrapie in sheep in portugal.	experimental transmission of bovine spongiform encephalopathy to sheep has prompted the implementation of a surveillance plan of scrapie in small ruminants by the european union in all member states. since its start over 30,000 animals have been tested, and the first seven cases of sheep with detectable prp(res) deposition in the central nervous system have been identified in portugal. notably, the pattern of prp(res) distribution in the brainstem was different from that previously described for ...	2004	15483267
identification of up-regulated genes by array analysis in scrapie-infected mouse brains.	the major neuropathological features of the transmissible spongiform encephalopathies (tses) are well documented, however, the underlying molecular events are poorly defined. we have applied cdna expression arrays and quantitative rt-pcr to the study of gene expression in the brain, and more specifically in the hippocampus, of the well-characterized me7/cv mouse model of scrapie. the number of genes showing consistent, scrapie-associated changes in expression was limited, and was primarily restr ...	2004	15488032
on scrapie interference and artificial prions.	the mechanisms responsible for neuronal death in transmissible spongiform encephalopathies (tses) are still not completely understood, and at least two major hypotheses have been formulated, based on the peculiar aspects of prion protein biology. in fact, the neuronal spreading of the prion conformational change may lead either to gain toxic properties, or to loose the normal function of this protein. in order to investigate the relative contribution of these two opposite mechanisms, two theoret ...	2004	15488657
prp polymorphisms in spanish sheep affected with natural scrapie.		2004	15493607
[influence of prion protein gene polymorphisms on performance traits in german meat sheep breeds].	prp polymorphisms influence the scrapie susceptiblility of sheep. the objective of this study was to analyse the association between performance traits and the prp genotype in the sheep breeds german black-headed and german white-headed mutton, bleu du maine, german mutton merino, leine, texel and suffolk from lower saxony and westphalia. we analysed performance traits such as scores for muscle mass, type and wool quality and the calculated daily weight gain using linear animal models. in all se ...	2004	15503534
prion replication alters the distribution of synaptophysin and caveolin 1 in neuronal lipid rafts.	the main event in the pathogenesis of prion diseases is the conversion of the cellular prion protein (prp(c)) into the abnormal, protease-resistant prion protein (prp(res)). prp(c) is a gpi-anchored protein located in lipid rafts or detergent-resistant membranes (drms). here we describe the association of prp with drms in neuronal cell bodies and axons during the course of murine scrapie and its relation with the distribution of the prp-interacting proteins caveolin 1 and synaptophysin. scrapie ...	2004	15509552
distribution of vascular amyloid in scrapie-affected sheep with different genotypes.	vascular amyloidosis in the brain is a pathological feature of ovine scrapie. its occurrence varies between sheep, but whether this variation reflects differences in the host or the infecting scrapie strain (or both) is not clear. to investigate whether amyloidosis, like vacuolation and prpsc distribution, is associated with genotype, the brains from 131 sheep representing a range of genotypes commonly associated with scrapie were examined histologically and immunohistochemically. vascular amylo ...	2004	15511535
cellular prion protein/laminin receptor: distribution in adult central nervous system and characterization of an isoform associated with a subtype of cortical neurons.	the 67-kda lr protein was originally discovered as a non-integrin laminin receptor. several more recent in vitro studies demonstrated the function of 67-kda lr and its related 'precursor' form 37-kda lrp as receptors of cellular prion protein and their implication in abnormal prion protein propagation in vitro. in addition, expression of both proteins was shown to increase considerably in the brain of scrapie-infected mice and hamsters. while lrp/lr are thus likely to play important roles in neu ...	2004	15548204
nmr solution structure and membrane interaction of the n-terminal sequence (1-30) of the bovine prion protein.	the structure and membrane interaction of the n-terminal sequence (1-30) of the bovine prion protein (bprpp) has been investigated by nmr spectroscopy in phospholipid membrane mimetic systems. cd spectroscopy revealed that the peptide adopts a largely alpha-helical structure in zwitterionic bicelles as well as in dhpc micelles but has a less degree of alpha-helix structure in partly charged bicelles. the solution structure of bprpp was determined in dhpc micelles, and an alpha-helix was found be ...	2004	15554701
molecular classification of scrapie strains in mice using gene expression profiling.	transmissible spongiform encephalopathy strains demonstrate specific prion characteristics, each with specific incubation times, and strain-specific patterns of deposition of the misfolded isoform of prion, prpsc, in the brains of infected individuals. different biochemical properties, including glycosylation profiles and the degree of proteinase resistance, have been shown to be strain-specific. however, no relationship between these properties and the phenotypic differences in the subsequent d ...	2004	15555574
decontamination of surgical instruments from prion proteins: in vitro studies on the detachment, destabilization and degradation of prpsc bound to steel surfaces.	effective reprocessing of surgical instruments ensuring elimination of inadvertent contamination with infectious agents causing transmissible spongiform encephalopathies (tses) is essential for the prevention of iatrogenic transmission of creutzfeldt-jakob disease (cjd) or its new variant (vcjd) from asymptomatic carriers. in a search for effective yet instrument-friendly and routinely applicable reprocessing procedures, we used an in vitro carrier assay to assess the decontamination activity ex ...	2004	15557254
advances in screening test development for transmissible spongiform encephalopathies.	the blood of patients with transmissible spongiform encephalopathy or prion disease can no longer be considered free of infectivity. there have been two recent reports of highly probable transfusion-associated iatrogenic variant creutzfeldt-jakob disease infections, and there is supporting experimental evidence of scrapie transmission by the transfusion of blood from sheep with naturally occurring disease. in the absence of a preclinical diagnostic test for transmissible spongiform encephalopath ...	2004	15566331
complement component c5 is not involved in scrapie pathogenesis.	during transmissible spongiform encephalopathy (tse) infections the accumulation of abnormal prion protein within the brain is often accompanied by severe neurodegeneration. studies have implicated complement, including the membrane attack complex (mac, c5b-c9), in inducing pathology in some neurodegenerative diseases. recent studies show the mac is localized on neurons in the brains of tse patients implicating complement-mediated cell lysis in tse neuropathology. to determine the role of the ma ...	2004	15568618
two irish cases of scrapie resembling nor98.		2004	15573787
infectivity studies of both ash and air emissions from simulated incineration of scrapie-contaminated tissues.	we investigated the effectiveness of 15 min exposures to 600 and 1000 degrees c in continuous flow normal and starved-air incineration-like conditions to inactivate samples of pooled brain macerates from hamsters infected with the 263k strain of hamster-adapted scrapie with an infectivity titer in excess of 10(9) mean lethal doses (ld50) per g. bioassays of the ash, outflow tubing residues, and vented emissions from heating 1 g of tissue samples yielded a total of two transmissions among 21 inoc ...	2004	15575075
differences in scrapie-induced pathology of the retina and brain in transgenic mice that express hamster prion protein in neurons, astrocytes, or multiple cell types.	prion protein (prp) is expressed in many tissues and is required for susceptibility to scrapie and other prion diseases. to investigate the role of prp expression in different cell types on pathology in retina and brain after scrapie infection, we examined transgenic mice expressing hamster prp from the prp promoter (tg7), the neuron-specific enolase promoter (tgnse), or the astrocyte-specific glial fibrillary acidic protein promoter (tggfap). after intraocular inoculation with hamster scrapie, ...	2004	15579448
biology of prpsc accumulation in two natural scrapie-infected sheep flocks.	sheep scrapie is a prion disease that requires interaction of exogenous prions with host prion protein (prp) supporting prion formation. disease is associated with deposition of a host-generated conformational variant of prp, prpsc, in a variety of tissues, including brain, resulting in fatal spongiform encephalopathy. efficiency of prpsc formation is determined by polymorphisms in the prp-coding sequence. this article adds to previous data of natural sheep scrapie, concentrating on the effect o ...	2004	15586562
recognition of the nor98 variant of scrapie in the swedish sheep population.	within the framework of the active surveillance for transmissible spongiform encephalopathies in sheep in sweden, 4 cases of the atypical form of scrapie, nor98, were identified during 2003. nor98 is a recently recognized and poorly understood variant of scrapie, first described in norway. the cases were positive by the rapid test (enzyme-linked immunosorbent assay). immunohistochemical staining showed diffuse thin-granular staining of the cerebellar cortex. western immunoblotting analysis of sp ...	2004	15586572
dual nature of the infectious prion protein revealed by high pressure.	crude brain homogenates of terminally diseased hamsters infected with the 263k strain of scrapie (prp(sc)) and purified prion fibrils were heated or pressurized at 800 megapascals and 60 degrees c for 2 h in different buffers and in water. prion proteins (prp) were analyzed for their proteinase k resistance in immunoblots and for their infectivity in hamster bioassays. a notable decrease in the proteinase k resistance of unpurified prion proteins, probably because of pressure-induced changes in ...	2004	15598650
protease-resistant human prion protein and ferritin are cotransported across caco-2 epithelial cells: implications for species barrier in prion uptake from the intestine.	foodborne transmission of bovine spongiform encephalopathy (bse) to humans as variant creutzfeldt-jakob disease (cjd) has affected over 100 individuals, and probably millions of others have been exposed to bse-contaminated food substances. despite these obvious public health concerns, surprisingly little is known about the mechanism by which prp-scrapie (prp(sc)), the most reliable surrogate marker of infection in bse-contaminated food, crosses the human intestinal epithelial cell barrier. here ...	2004	15601934
transmissible spongiform encephalopathies: scrapie control under new strain.		2004	15602534
scrapie case similar to nor98 diagnosed in belgium via active surveillance.		2004	15605538
the modern landscape of transfusion-related iatrogenic creutzfeldt-jakob disease and blood screening tests.	the idea that blood in naturally occurring transmissible spongiform encephalopathies is not infectious has imploded in the face of recent transmissions from the blood of naturally occurring scrapie in sheep and of variant creutzfeldt-jakob disease in humans. although donor exclusion criteria ensure that the number of any further iatrogenic cases will be small, the risk of future blood-borne disease transmissions could be entirely eliminated by a diagnostic preclinical screening test. a variety o ...	2004	15666660
recombinant alkaline serine protease ii degrades scrapie isoform of prion protein.	an efficient escherichia coli expression system for the production of mature-type alkaline serine protease ii (masp ii) has been constructed. complementary deoxyribonucleic acid-encoding masp ii was inserted into the inducible bacterial expression vector pge-30. after introduction into e. coli, the plasmid was expressed by isopropyl-1-thio-beta-d-galactopyranoside, and the recombinant product was purified using a ni-nitrilotriacetic acid column. the purified product had the expected nh2-terminal ...	2004	15723565
immunohistochemical studies of scrapie archival material from irish arq/arq sheep for evidence of bovine spongiform encephalopathy-derived disease.	since scrapie and bovine spongiform encephalopathy (bse) in sheep are clinicopathologically indistinguishable, bse in sheep may have been misdiagnosed as scrapie. disease-specific prion protein (prp(d)) patterns in archival tissues of 38 irish arq/arq sheep diagnosed as scrapie-affected were compared to those in four dutch bse-challenged sheep. when medulla oblongata was immunolabelled with an antibody directed against amino acids 93-99 of ovine prion protein (ovprp), intraneuronal prp(d) was ap ...	2004	15894021
comparative histological studies of mechanically versus manually processed sheep intestines used to make natural sausage casings.	the natural sausage casings industry is large and worldwide, and casings prepared from the small intestine of sheep form a large part of it. food safety authorities in several countries have been concerned about the risk to consumers from the bovine spongiform encephalopathy (bse) agent. although this agent could enter the european small ruminant population via infected feed, there is no evidence that it has. because the bse agent introduced experimentally into sheep and goats has a tissue distr ...	2004	15633681
an overview of transmissible spongiform encephalopathies.	transmissible spongiform encephalopathies (tses) are fatal neurodegenerative disorders of humans and animals associated with an accumulation of abnormal isoforms of prion protein (prp) in nerve cells. the pathogenesis of tses involves conformational conversions of normal cellular prp (prp(c)) to abnormal isoforms of prp (prp(sc)). while the protein-only hypothesis has been widely accepted as a causal mechanism of prion diseases, evidence from more recent research suggests a possible involvement ...	2004	15984319
selecting for scrapie-resistant sheep.		2004	15518412
labeling of the scrapie-associated prion protein in vitro and in vivo.	prion diseases are a group of infectious neurodegenerative diseases that affect both animals and humans. a characteristic of prion diseases is the aggregation and accumulation of a disease-associated isoform of the prion protein in the brains of infected individuals. the amyloid imaging probe (trans,trans)-1-bromo-2,5-bis-(3-hydroxycarbonyl-4-hydroxy)styrylbenzene (bsb) has shown potential in the diagnosis of other amyloid disorders and we hypothesized that this compound would be effective in la ...	2004	15519752
altered interaction and expression of proteins involved in neurosecretion in scrapie-infected gt1-1 cells.	prions cause transmissible and fatal diseases that are associated with spongiform degeneration, astrogliosis, and loss of axon terminals in the brains. to determine the expression of proteins involved in neurosecretion and synaptic functions after prion infection, gonadotropin-releasing hormone neuronal cell line subclone (gt1-1) was infected with the rml scrapie strain and analyzed by western blotting, real time pcr, and immunohistochemistry. as revealed by western blotting of lysates exposed t ...	2005	15528199
tissue safety in view of cjd and variant cjd.	epidemiological studies on human transmissible spongiform encephalopathies (creutzfeldt-jakob disease, cjd) have shown that the agent could be transmitted by highly infectious tissues like brain, spinal cord or retina and medicinal products derived from these tissues (i.e. human growth hormone, dura mater). a few cases of transmission of cjd by neurosurgical instruments have been reported. the transmission of the agent of variant cjd, which is suspected to be transmitted by bse-contaminated food ...	2005	16151959
an aggregation-specific enzyme-linked immunosorbent assay: detection of conformational differences between recombinant prp protein dimers and prp(sc) aggregates.	the conversion of the normal cellular prion protein, prp(c), into the protease-resistant, scrapie prp(sc) aggregate is the cause of prion diseases. we developed a novel enzyme-linked immunosorbent assay (elisa) that is specific for prp aggregate by screening 30 anti-prp monoclonal antibodies (mabs) for their ability to react with recombinant mouse, ovine, bovine, or human prp dimers. one mab that reacts with all four recombinant prp dimers also reacts with prp(sc) aggregates in me7-, 139a-, or 2 ...	2005	16160162
anchors away--of plaques and pathology in prion disease.		2005	16162891
inhibitors of the mitogen-activated protein kinase kinase 1/2 signaling pathway clear prion-infected cells from prpsc.	prions represent a unique class of infectious agents in which the normal cellular prion protein (prpc) is converted to an abnormal isoform (prpsc), which accumulates in the brain and constitutes the major, if not the only, component of the infectious particle. factors that still remain to be identified may facilitate the conversion of prpc to prpsc. in the present study, we first demonstrated that a growth factor of the neurotrophin family, brain-derived neurotrophic factor (bdnf), stimulates th ...	2005	16162927
prion diseases.	prion diseases are degenerative disorders of the nervous system caused by transmissible particles that contain a pathogenic isoform of the prion protein, a normal constituent of cell membranes. the most common human prion disease is creutzfeldt-jakob disease (cjd). most cases are sporadic with unknown mode of transmission, 10-15% of cases are inherited, and a small number have been transmitted by medical procedures. the spread of human prion diseases through consumption of infected material has ...	2005	16168932
elimination of transmissible spongiform encephalopathy infectivity and decontamination of surgical instruments by using radio-frequency gas-plasma treatment.	it has now been established that transmissible spongiform encephalopathy (tse) infectivity, which is highly resistant to conventional methods of deactivation, can be transmitted iatrogenically by contaminated stainless steel. it is important that new methods are evaluated for effective removal of protein residues from surgical instruments. here, radio-frequency (rf) gas-plasma treatment was investigated as a method of removing both the protein debris and tse infectivity. stainless-steel spheres ...	2005	16033987
bovine spongiform encephalopathy--some surprises for biochemists.	bovine spongiform encephalopathy (bse) is typical of the dementias that affect both animals and man; scrapie in sheep, creutzfeldt-jakob disease in man. global efforts have been made to determine the nature of the active agents in these diseases. at present the 'protein only hypothesis' of prusiner holds. it was a surprise that a protein could per se be the active agent but other surprises for our traditional teaching of biochemistry arose. these are explained in a brief summary of our present u ...	2005	16036610
comparison of protease-resistant prion protein inhibitors in cell cultures infected with two strains of mouse and sheep scrapie.	the transmissible spongiform encephalopathies (tses) are fatal neurodegenerative diseases. a primary therapeutic target for tse intervention has been a protease-resistant form of prion protein known as prp(sc) or prp-res. in vitro testing of mouse scrapie-infected cell cultures has identified many prp-res inhibitors that also have activity in vivo. here we identify 32 new inhibitors of two strains of mouse scrapie prp-res. furthermore, to investigate the species-specificity of these and other pr ...	2005	16039063
probing prpsc structure using chemical cross-linking and mass spectrometry: evidence of the proximity of gly90 amino termini in the prp 27-30 aggregate.	elucidation of the structure of prp(sc) continues to be one of the most important and difficult challenges in prion research. this task, essential for gaining an understanding of the basis of prion infectivity, has been hampered by the insoluble, aggregated nature of this molecule. we used a combination of chemical cross-linking, proteolytic digestion, and mass spectrometry (maldi-tof and nanolc-esi-qqtof), in an attempt to gain structural information about prp 27-30 purified from the brains of ...	2005	16042387
animal breeding and disease.	single-locus disorders in domesticated animals were among the first mendelian traits to be documented after the rediscovery of mendelism, and to be included in early linkage maps. the use of linkage maps and (increasingly) comparative genomics has been central to the identification of the causative gene for single-locus disorders of considerable practical importance. the 'score-card' in domestic animals is now more than 100 disorders for which the molecular lesion has been identified and hence f ...	2005	16048793
pathogenesis and transfusion risk of transmissible spongiform encephalopathies.	the genesis (and pathogenesis) of sporadic and familial forms of human transmissible spongiform encephalopathy (tse) is unknown, but the disease process may originate spontaneously in the brain as a statistically random event involving misfolding and amyloid formation of the "prion" protein. the pathogenesis of environmentally acquired tse depends on the route of infection and is likely to involve both neural and haematogenous paths of neuro-invasion. blood infectivity is well documented in expe ...	2005	16050152